Decorative mattress border fabric with inherent flame barrier

ABSTRACT

A flame barrier substrate consisting principally of non-fire-retardant (non-FR) fiber with fire-resistant properties and affinity for sublistatic dyes. The flame barrier substrate includes a balanced fine core-spun yarn whose face may include fibers with an affinity for dyes, e.g., sublistatic dyes. The balanced fine core-spun yarn may also include a heat-stable core enveloped in a sheath of low-temperature-resistant fibers such as, for example, non-fire-retardant (non-FR) fibers. The balanced fine core-spun yarns may be further combined with other balanced fine core-spun yarns made with a sheath of fire-retardant fibers for added flame barrier performance. This flame barrier substrate may be constructed to concentrate the dye-receptive yarns on the technical face of the fabric for optimal aesthetics.

CROSS REFERENCE TO PRIOR APPLICATION

This application claims priority to and the benefit thereof from U.S. provisional patent application No. 61/955,441, filed Mar. 19, 2014 titled “DECORATIVE MATTRESS BORDER FABRIC WITH INHERENT FLAME BARRIER,” the entirety of which is hereby incorporated herein by reference.

BACKGROUND OF THE DISCLOSURE

1.0 Field of the Disclosure

The present disclosure relates generally to a flame barrier substrate, and more specifically, it relates, among other things, to a flame barrier substrate made using balanced fine core-spun yarns whose sheath fibers are principally non-fire-retardant (non-FR) and have an affinity for sublistatic dyes.

2.0 Related Art

United States mattress manufacturers are required to meet federal flammability regulations for mattresses sold in the United States. Mattress manufacturers have employed various methods to provide mattress constructions with fire-retardant properties, with solutions ranging from knitted flame barrier interliners, to barriers knitted into decorative tickings, to highloft nonwoven battings, to stitchbonded nonwovens, or to laminates involving any of these combinations. In the case of innerspring mattresses, manufacturers have gravitated toward quilted composites consisting of a decorative ticking backed with a high-loft fire-retardant batting, with or without a nonwoven scrim behind the high-loft. This quilted approach is used for the sleep surface(s), but is also a technique specifically employed in the border (i.e., the side and end “walls” of the mattress structure) to help ensure compliance with full-scale mattress burn tests. Although this technique can be effective, mattress makers often complain that quilting is an expensive, time consuming and wasteful process. Other suppliers to the industry have sought to use lamination of the high-loft to the border ticking. While lamination is more efficient than quilting, laminated composites are generally less durable than quilted composites, and they depend on longer production runs for their cost-efficiency.

Specialty sleep mattress constructions, i.e., those mattresses consisting principally of foam, or those mattresses whose sleep surfaces are principally unquilted foam, are made using stretchable fire-retardant flame barrier interliners. These articles are most frequently tubular knit fabrics made using inherently fire-retardant (FR) core-spun yarns, or from combinations of core-spun and other yarns. Mattress manufacturers often prefer these solutions for specialty mattresses, because of their simplicity and ease of application, and also because the stretch and recovery of the barrier structures enables consumers to feel the responsiveness of the foams they use. The disadvantage of these types of barriers lies in their expense compared to high-loft solutions. Mattress manufacturers would prefer to deploy these barriers only where they would provide a marketing advantage or consumer benefit.

Ticking manufacturers have produced low-cost, printed, stitchbonded tickings, to some effect, but these are generally not seen as suitable for top-quality mattress brands. These tickings are also printed on rotary screen print or flexographic print ranges, making larger lot sizes more economical, but creating a risk of fashion obsolescence if the entire printing run is not sold in a timely manner.

The producers of integrated barrier knit tickings have sought to address this issue by knitting heavier-duty tickings, specifically for use as mattress borders. These products are effective as flame barriers, but they are still subject to minimum run sizes and subject to the same fashion obsolescence risk, as the design is imparted at the time the fabric is formed.

Meanwhile, mattress manufacturers have continued to seek lower-cost methods to provide mattresses with fire-retardant (FR) properties and aesthetic appearances while preserving or enhancing the comfort and perceived value of their respective mattress constructions.

It is known in the textile industry to produce fire-retardant and or flame-resistant fabrics for use as mattress tickings, bedspreads, furniture, and the like, by using yarn formed of natural or synthetic fibers and then treating the fabric with fire retarding chemicals, such as halogen-based and/or phosphorus-based chemicals. This type of fabric is heavier than similar types of non-fire retardant fabrics, and has a limited wear life. Also, this type of fabric typically melts or forms brittle chars which break away when the fabric is burned.

It is also known to form fire-resistant fabrics of fire-resistant relatively heavy weight yarns in which a low temperature-resistant fiber is ring spun around a core of continuous filament fiberglass. However, this type of ring spun yarn has torque imparted thereto during the spinning process and is very lively. Because of the lively nature of the yarn, it is necessary to ply “S” and “Z” ring spun yarns together so that the torque and liveliness in the yarn is balanced in order to satisfactorily weave or knit the yarn into the fabric, without experiencing problems of tangles occurring in the yarn during the knitting or weaving process. This plying of the “S” and “Z” yarns together results in a composite yarn which is so large that it cannot be used in the formation of fine textured, lightweight fabrics. In some instances the fiberglass filaments in the core protrude through the natural fiber sheath. It is believed that the problem of protruding core fibers is associated with the twist, torque and liveliness being imparted to the fiberglass core during the ring spinning process.

It is also known to produce coated upholstery fabrics by weaving or knitting a substrate or scrim of a cotton or cotton and polyester blend yarn. This scrim is then coated with a layered structure of thermoplastic polyvinyl halide composition, such as polyvinyl chloride (PVC). This coated upholstery fabric has very little, if any, fire-resistance and no flame barrier properties. In addition to the coating chemical having a limited shelf life, the chemical coatings pose a safety hazard in case of contact with skin.

Yet another solution involves the creation of core spun yarns using sheath fiber that includes fire-resistant fibers such as, for example, rayon, modacrylic, aramids, melamine, phenolic, and so on. However, this solution can often be costly due to, for example, higher raw material costs.

Furthermore, currently available fire-retardant and or flame-resistant fibers are unable to be printed using sublistatic heat transfer or digital printing because these fibers are not chemically or physically receptive to the dyes used under normal processing conditions. These printing methods make use of sublistatic dyes to impart decorative and/or functional patterns.

Heat-transfer-printing may use dyestuffs, which may, at a specified process temperature, sublimate and allow for creation of a pattern on a flame barrier substrate. In such a printing process, a substrate may be fed into a transfer printing range that presses the dye-infused transfer paper, which includes a specific pattern and/or design to the substrate and exposes the joined substrate-paper combination to a specified sublimation temperature for a predetermined dwell time. The sublimation of the dyestuff causes the pattern/design to impregnate the receptive fibers in the substrate, thereby creating a precise likeness of the design on the transfer paper on the substrate. This process may be carried out on a batch or on a continuous basis.

These aesthetic patterns are often desired in, e.g., mattress tickings, bedspreads, furniture, and the like. Unlike rotary screen printing or other well-known printing technologies, sublistatic printing enables shorter lead times and shorter print runs for increased styling flexibility with less waste.

In order to address the root cause of, for example, inability to easily heat-transfer print decorative elements onto fabrics with fire-retardant properties, an unfulfilled need exists for a fire-retardant core-spun yarn that can receive the dyestuffs used to print a decorative and/or functional pattern onto the fabric made from the yarn.

SUMMARY OF THE INVENTION

In one aspect, the present disclosure provides an open flame barrier fabric with affinity for sublistatic dyes. The flame barrier substrate includes a balanced fine core-spun yarn, a sheath of low-temperature-resistant fibers. For purpose of this invention, low-temperature-resistant fibers may include fibers that would melt or char at or near typical combustion temperatures. Polyester melts at 482-550° F., and modacrylic fibers melt at 371-410° F. By contrast fiberglass softens at 1,224° F. This designation may be used to distinguish the sheath material from the core which has a higher melting point, wherein the balanced fine core-spun yarn may include a heat-stable core enveloped in the sheath of low-temperature-resistant fibers.

The sheath of low-temperature-resistant fibers may include fibers with an affinity for sublistatic dyes. The low-temperature-resistant fibers comprise non-fire retardant (non-FR) fibers. The non-FR fibers may include at least one of: polyester, nylon, and any other fiber that has an affinity for sublistatic dyes. The heat-stable core may include at least one of: multi-filament fiberglass, aramid, and steel. The flame barrier substrate may be configured to be used as a decorative outer fabric that comprises the side and end walls of a mattress. The non-fire retardant fibers may be configured to melt in presence of a flame thereby reducing air permeability and simultaneously depriving potential fuel of oxygen while creating a physical impediment to the progress of the flame to potential fuel within a mattress or other upholstered article thereby creating a flame barrier. The yarn's heat stable core may provide a supporting structure or lattice for melted and congealed non-fire retardant fibers and provide structural stability (for e.g., charred material) to maintain a barrier to the flame.

In one aspect, the present disclosure provides a method for manufacturing a flame barrier substrate with decorative and or functional patterns. The method for manufacturing the flame barrier substrate with decorative and/or functional patterns includes providing a balanced fine core-spun yarn wherein the core-spun yarn includes a heat stable core enveloped in a sheath of fibers, and printing a decorative and or functional pattern onto the fabric made from balanced fine core-spun yarn. The fibers may include non-fire retardant fibers with an affinity for sublistatic dyes. The fabric may be configured to be engineered in a way to concentrate the sheath of non-fire retardant fibers with an affinity for sublistatic dyestuffs on one side of the substrate, thereby creating a decorative, technical face of the fabric. The printing may include digital printing, rotary screen printing, heat-transfer printing, and the like. The heat-stable core may include at least one of: multi-filament fiberglass, aramid, and steel.

In one aspect, the present disclosure provides a method for manufacturing a flame barrier substrate with decorative and or functional patterns. The method for manufacturing a flame barrier substrate with decorative and/or functional patterns includes providing a balanced fine core-spun yarn wherein the core-spun yarn includes a heat stable core, providing a sheath of non-FR fibers with an affinity for sublistatic dyestuffs and a second balanced fine core spun yarn wherein the core-spun yarn includes a heat stable core, providing a sheath of fibers with fire-retardant (FR) properties, and combining the two core spun yarn types in a woven substrate. The structure of the fabric may be engineered in such a way as to concentrate the dye receptive warp yarns on the technical face of the fabric, while concentrating the filling yarns containing FR sheath fibers on the technical back of the fabric. This technique may enable sublistatic printing of the technical face with optimal color yield and image fidelity, as inherently FR fibers resist sublistatic dyestuffs under normal processing conditions. The aforementioned technique minimizes the dye-resistive fibers' presence on the technical face of the substrate.

In one aspect, a flame barrier substrate is provided that includes a balanced fine core-spun yarn and a sheath of low-temperature-resistant fibers comprising non-fire retardant fibers with an affinity for sublistatic dyes wherein the non-fire retardant fibers are configured to melt in presence of a flame reducing air permeability and simultaneously depriving the potential fuel of oxygen while creating a physical impediment to progress of the flame to potential fuel within a mattress or other upholstered article thereby creating a flame barrier, wherein the balanced fine core-spun yarn comprises a heat-stable core enveloped in the sheath of low-temperature-resistant fibers.

Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the detailed description and drawings. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the disclosure, are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the detailed description serve to explain the principles of the disclosure. No attempt is made to show structural details of the invention in more detail than may be necessary for a fundamental understanding of the disclosure and the various ways in which it may be practiced.

FIG. 1A shows an example of a SEM photomicrograph of the cross-section of a core spun flame barrier yarn substrate with affinity for sublistatic dyes in accordance with the principles of this disclosure.

FIG. 1B shows a schematic example of a flame barrier yarn substrate with affinity for sublistatic dyes in accordance with the principles of this disclosure.

FIG. 2 discloses an example of a flame barrier substrate constructed according to principles of the disclosure.

FIG. 3 shows an example photograph of a flame barrier substrate constructed according to principles of the disclosure.

FIG. 4A shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 4B shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 5A shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 5B shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 6A shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 6B shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 7A shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 7B shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 8A shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 8B shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 9A shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 9B shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 10A shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 10B shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 11A shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

FIG. 11B shows an example of flammability test result for a flame barrier substrate constructed according to principles of the disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The embodiments of the invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and detailed in the following attached description. It should be noted that the features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure the embodiments of the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those of skill in the art to practice the embodiments of the invention. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the invention.

The terms “including”, “comprising” and variations thereof, as used in this disclosure, mean “including, but not limited to,” unless expressly specified otherwise.

The terms “a”, “an”, and “the,” as used in this disclosure, means “one of more”, unless expressly specified otherwise.

Although process steps, method steps, algorithms, or the like, may be described in a sequential order, such processes, methods and algorithms may be configured to work in alternate orders. In other words, any sequence or order of steps that may be described does not necessarily indicate a requirement that the steps be performed in that order. The steps of the processes, methods or algorithms described herein may be performed in any order practical. Further, some steps may be performed simultaneously.

When a single device or article is described herein, it will be readily apparent that more than one device or article may be used in place of a single device or article. Similarly, where more than one device or article is described herein, it will be readily apparent that a single device or article may be used in place of the more than one device or article. The functionality or the features of a device may be alternatively embodied by one of more other devices which are not explicitly described as having such functionality or features.

The disclosure provides examples of a flame barrier substrate composed principally of non-fire-retardant (non-FR) fiber. The non-FR fiber may make up at least 60% of the product substrate. Further, core spun yarns may be made with non-FR fiber sheaths having an affinity for sublistatic dyes. If it is deemed desirable or necessary to mix dye-receptive non-FR sheath warp yarns with filling yarns whose sheaths contain FR fibers that resist sublistatic dyes (in whole or in part), the structure of the fabric may be engineered to concentrate the dye receptive yarns on the technical face of the fabric.

An aspect of the present disclosure provides a flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes. The flame barrier substrate may include a balanced fine core-spun yarn whose sheath may include non-FR fibers with an affinity for dyes, e.g., sublistatic dyes (as shown in, for example, FIGS. 1A and 1B).

The balanced fine core-spun yarn may also include a heat-stable core enveloped in a sheath of low-temperature-resistant fibers such as, for example, non-fire retardant (non-FR) fibers in a sheath-to-core ratio ranging from 75:25-to-25:75. The balanced fine core-spun yarn may comprise, for example, at least 60% non-FR fibers with an affinity for sublistatic dyes. This will result in higher concentration of dye-receptive non-FR fibers on the surface of the balanced fine core-spun yarn which will better facilitate printing of sublistatic dyes onto the substrate made from these yarns.

The non-FR fibers may include polyester, nylon, and any other fiber that has an affinity for sublistatic dyes. The heat-stable core may include multi-filament fiberglass (silica), aramid, steel, and the like.

The flame barrier substrate may function as a flame barrier by virtue of the cores' maintenance of a lattice or scrim that does not melt, crack, breach or deform in the presence of an ignition source. For purposes of quantifying the level of performance, the NIST Burner cited in 16 CFR 1633 is typical of the ignition exposures that the flame barrier substrate is intended to withstand.

The flame barrier substrate may be used, e.g., as a mattress border, a decorative outer fabric that comprises the side and end “walls” of a mattress. The flame barrier substrate can provide aesthetic benefits as part of the mattress's exterior, as well as function as a flame barrier. The flame barrier substrate may also be used as the outer ticking of an entire mattress, or as an upholstery fabric for furniture such as chair cushions, sofas, wheelchair cushions, and so on. The flame barrier substrate may be further configured to be used as a decorative outer fabric of furniture. The flame barrier substrate may also be configured to be used in e.g., office interiors.

An example of the present disclosure provides a functional flame barrier fabric made principally using core-spun yarns, the sheaths of which may include primarily synthetic fibers with an affinity for sublistatic dyes even if these dye accepting fibers may not be inherently fire-retardant or flame-resistant. The resulting flame barrier fabric may be made decorative in small-batch heat-transfer printing runs in order to create a decorative flame barrier fabric with improved aesthetics, e.g., sharper color, increased color yield, sharper printed design, improved colorfastness, and the like.

The synthetic fibers with affinity for dyes currently used in sublistatic printing may include polyester, nylon, and the like. The synthetic fibers may be wrapped around a heat stable core to hold these fibers in place on exposure to flame. The fibers' tendency to melt in the presence of the flame is utilized advantageously as the flow of melting sheath fiber is used to fill in the air spaces—the interstices—between yarns, restricting the amount of air that can be drawn through the barrier layer into the combustible material within the barrier envelope. The fabric made from these yarns should have sufficient textile cover—that is, the percentage of the area of one square inch of fabric that is covered by yarn—to limit air permeability. The limited air permeability will help deprive incipient fire of oxygen thereby slowing down or stopping the fire from growing. The resulting fabric may exhibit cover greater than, e.g., about 80% cover, resulting in air permeability less than, e.g., about 90 cubic feet per minute (CFM).

In another embodiment of the present disclosure, a flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes is provided. The flame barrier substrate may include a combination of dye-friendly core spun yarns and core spun yarns made using inherently fire-retardant (FR) fibers. The combination may be carried out by creating a warp using non-FR sheath fibers in all core spun warp yarns. Filling yarns may include these same yarns, but may also be alternated with core spun yarns made using inherently FR fibers or blends of FR fibers in the sheath. The FR fibers may include modacrylics, treated cotton or rayon, fire-retardant lyocell, meta-aramids, para-aramids, fluoropolymers and copolymers thereof, chloropolymers, polybenzimidazole, polyimides, polyamideimides, partially oxidized polyacrylonitriles, novoloids, poly (p-phenylene benzobisoxazoles), poly (p-phenylene benzothiazoles), polyphenylene sulfides, flame-retardant viscose rayons, polyvinyl chloride homopolymers and copolymers thereof, polyetheretherketones, polyketones, polyetherimides, polylactides, and combinations thereof, and the like.

Part of this embodiment may include making the dye receptive yarns more numerous than the inherently FR core-spun yarns. This can be accomplished by making warp yarns more numerous than filling yarns, but the percentage of warp and filling yarns made with dye-receptive non-FR fiber sheaths will vastly outnumber the yarns containing FR fiber. For example, non-FR-clad yarns may include 80% of the total fabric mass.

In addition, through careful fabric design, these more numerous non-FR dye receptive core yarns may be woven or knitted so that they predominate on the face of the fabric, directing yarns that contain inherently fire-retardant fibers to the reverse. In this way, the substrate would have a decorative technical face (e.g., the printed or printable side) and a reverse side, the technical back of the fabric.

In yet another embodiment of the present disclosure, a woven substrate with fire-retardant (FR) properties is disclosed. The woven substrate includes a warp wherein the warp includes dye-receptive flame barrier yarns. The dye-receptive flame barrier yarns may constitute the totality or the majority of the fabric's warp. These more numerous dye receptive yarns would be concentrated on the face of the fabric through the creation of warp-face fabrics, such as twills (as shown in, e.g., FIG. 2-3) or sateens. The perpendicular fill yarns could include, for example, a mix of dye-receptive non-FR core-spun yarns, core-spun yarns made with inherently fire-retardant fibers and or non-core-spun yarns in a variety of blend compositions and sizes to achieve desired physical, mechanical and flame resistant properties. The population of yarns may include at least 60% non-FR core-spun yarns. There may be interlacings between warp and filling yarns wherein each contains a heat-stable core so that the substrate may function as an effective flame barrier.

In yet another embodiment of the present disclosure, a knitted substrate is disclosed. The knitted substrate may include dye receptive flame barrier core spun yarns knitted with other core-spun yarns made with inherently fire-retardant (FR) fibers to create a double face fabric. This manufacturing method may result in a concentration of dye-receptive flame barrier yarns on one face of the fabric to enable both better color saturation and sufficient char formation to restrict airflow. The total population of yarns in this embodiment may include at least 50% yarns made using non-FR dye receptive core spun yarns.

Further to the above embodiment, the dye receptive core spun yarns may be knitted alone in a tightly knitted construction as a single layer fabric, to fashion a knitted all-in-one ticking that would serve as an exterior decorative mattress cover fabric while serving simultaneously as a flame barrier. Similarly, this construction could also function as a flame barrier interliner.

Another aspect of the present disclosure provides a method for manufacturing a flame barrier substrate with decorative and or functional patterns. The method for manufacturing the flame barrier substrate with decorative and/or functional patterns includes providing a balanced fine core-spun yarn wherein the core-spun yarn includes a heat stable core enveloped in a sheath of non-FR fibers, and printing a decorative and or functional pattern onto the fabric made from these balanced fine core-spun yarns. The fibers may include non-fire-retardant fibers with an affinity for sublistatic dyes. The printing may include digital printing, rotary screen printing, heat-transfer printing, wet printing, flexographic printing techniques, and the like. By use of these printing technologies, the flame barrier substrate may be enhanced through the use of metallic, pearlescent or iridescent pigment formulations, and may also be printed with “puff printing” techniques to create designs with three-dimensional relief. Unlike rotary screen printing or other well-known printing technologies, sublistatic printing enables shorter print runs for increased styling flexibility with less waste.

FIGS. 1A and 1B disclose an example of a flame barrier yarn constructed according to principles of the disclosure. The flame barrier yarn may be typical Firegard® core-spun yarn. The cylindrical fibers may be silica (a/k/a glass fiber or fiberglass) and they may be surrounded by low-temperature resistant fibers. For purposes of this invention, low-temperature-resistant fibers are those fibers that would melt or char at or near typical combustion temperatures. This designation is intended to distinguish the sheath material from the core which would have a much higher melting point,

The flame barrier substrate may include a balanced fine core-spun yarn 100 wherein the core-spun yarn 100 includes a heat stable core 110 and a sheath of fibers with an affinity for sublistatic dyestuffs 120. The heat stable core 110 may include e.g., multi-filament fiberglass (silica), aramid, steel, and the like. The sheath of fibers 120 may include non-fire retardant (non-FR) fibers which may include e.g., polyester, nylon, and any other fabric that has an affinity for sublistatic dyes. The sheath of fibers 120 may also include fibers with fire-retardant (FR) properties e.g., modacrylics, treated cotton or rayon, fire-retardant lyocell, meta-aramids, para-aramids, fluoropolymers and copolymers thereof, chloropolymers, polybenzimidazole, polyimides, polyamideimides, partially oxidized polyacrylonitriles, novoloids, poly (p-phenylene benzobisoxazoles), poly (p-phenylene benzothiazoles), polyphenylene sulfides, flame-retardant viscose rayons, polyvinyl chloride homopolymers and copolymers thereof, polyetheretherketones, polyketones, polyetherimides, polylactides, and combinations thereof, and the like. These FR fibers may also be blended with non-FR fibers, for example, to enhance the formation of char on exposure to flame. These fibers can include those fibers with an affinity for sublistatic dyes, but they constitute a much smaller percentage of the fiber blend than contemplated in this invention.

The core-spun yarn 100 may include a combination of the sheath of non-fire retardant fibers 120 with an affinity for sublistatic dyestuffs and the heat resistant core 110. The sheath of fibers 120 may include, e.g., at least about 50% non-fire retardant fibers, such as, e.g., 60%, 70%, or 80%.

The structure of the fabric may be engineered in such a way as to concentrate the dye receptive warp yarns on the technical face of the fabric, while concentrating the filling yarns containing FR sheath fibers on the technical back of the fabric. This technique may enable sublistatic printing of the technical face with optimal color yield and image fidelity, as inherently FR fibers resist sublilstatic dyestuffs under normal processing conditions.

The structure of the fabric may be further engineered to modify the surface texture of the fabric to mimic that of e.g., woven linen.

As shown in FIG. 1B, the heat stable core 110 may be surrounded by the sheath of fibers 120. The perimeter formed by fibers 120 may be partially open or may be fully enclosed.

FIG. 2 discloses an example of a flame barrier substrate constructed according to principles of the disclosure. The flame barrier substrate may include a woven substrate 200 such as, for example, a twill weave. The woven substrate 200 may include a warp yarn 210 and a filling yarn 220. The warp yarn 210 may include non-fire retardant (non-FR) sheath fibers with an affinity for sublistatic dyes. The filling yarn 220 may also include non-FR fibers in its sheath; however, a weaving technique is disclosed wherein filling yarns made with non-FR sheaths can be alternated with core spun yarns made with FR fiber (or FR fiber blend) sheaths. The warp yarn 210 may be more numerous than the filling yarn 220 in order to make the dye receptive yarns more numerous than non-dye receptive yarns. In one embodiment, the non-FR fibers may include, e.g., up to 80% of the total fiber mass. Alternatively, the warp yarn 210 may be equal to or less than the amount of filling yarn 220, provided that the filling yarn 220 is composed of non-FR dye-receptive fiber in its sheath and the resultant fabric forces the filling yarns to the technical face. To function as an aesthetic flame barrier, the dye receptive yarns must predominate on one side of the substrate.

FIG. 3 shows an example photograph of a flame barrier substrate constructed according to principles of the disclosure. The flame barrier substrate includes a woven substrate 300 such as, for example, a twill weave. While FIG. 3 shows the woven substrate 300 in 2/1 Left Hand Twill configuration, the woven substrate 300 may also include e.g., 1/1 plain weaves, 2/1 Right-Hand Twill (RHT), oxford weaves, sateens, and so on. The woven substrate 300 may further include a warp yarn 310 and a filling yarn 320. In 2/1 LHT, the numerator indicates that the warp yarn 310 crosses over two filling yarns 320 and then under one filling yarn 320. It is noted that the texture imparted by the diagonal wales rising to the left (typical of a 2/1 Left-Hand Twill (LHT) is a result of each warp yarn's crossing two filling yarns in a stepwise sequence. As shown in FIG. 3, the interlacing of the warp yarn 310 and the filling yarn 320 may progress to the left, forming a set of distinct ascending diagonal lines (i.e., wales).

Example 1

A flammability test for requirements set forth in the 16 CFR 1633 on a non-limiting example of a flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes (the “test specimen”) is shown in Table 1.

TABLE 1 Test Results: Item Readings Limit Result Maximum Rate of Heat 24 200 Met Release (kW) Total Heat Release in 10 3.19 15 Met minutes (MJ)

The test specimen consisted of a single sided tight top mattress with bed base. The test specimen, after conditioning for not less than 48 hours, to 70° F. and 50% R.H., was placed underneath the collection hood. The test was started no more than 20 minutes after removal from the conditioning chamber. The specified pair of propane test burners was placed on the top panel and border as specified in the test protocol. The computer data acquisition system was started. After one minute of ambient data acquisition, the burners were ignited and left to burn for 70 seconds (top) and 50 seconds (border). After both burners were out the top burner was lifted and pinned and the apparatus was backed away from the specimen. The test was allowed to proceed until either all combustion ceased, 30 minutes passed, or the development of a fire of such size as to require suppression for the safety of the facility. The test specimen was placed under the open calorimeter and tested. At the time of testing, the ambient temperature was 72° F. with a relative humidity of 67%. The data recorded includes Heath Release Rate (HRR) and Total Heat Release (THR) as shown in FIGS. 4A and 4B.

After cooling, the mattress was observed to be damaged as follows:

Mattress Cover: 20% of the cover was consumed. Internal Components: 0% consumed. Foundation: 0% consumed.

Mattress Barrier: Intact.

As a conclusion, the sample specimen met the requirements set forth in the 16 CFR 1633, Standard for the Flammability (Open Flame) of Mattresses Sets.

Example 2

A flammability test for requirements set forth in the 16 CFR 1633 on a non-limiting example of a flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes (the “test specimen”) is shown in Table 4.

TABLE 4 Test Results: Item Readings Limit Result Maximum Rate of Heat 29 200 Met Release (kW) Total Heat Release in 10 4.09 15 Met minutes (MJ)

The test specimen consisted of a single sided tight top mattress with bed base. The test specimen, after conditioning for not less than 48 hours, to 70° F. and 50% R.H., was placed underneath the collection hood. The test was started no more than 20 minutes after removal from the conditioning chamber. The specified pair of propane test burners was placed on the top panel and border as specified in the test protocol. The computer data acquisition system was started. After one minute of ambient data acquisition, the burners were ignited and left to burn for 70 seconds (top) and 50 seconds (border). After both burners were out the top burner was lifted and pinned and the apparatus was backed away from the specimen. The test was allowed to proceed until either all combustion ceased, 30 minutes passed, or the development of a fire of such size as to require suppression for the safety of the facility. The test specimen was placed under the open calorimeter and tested. At the time of testing, the ambient temperature was 72° F. with a relative humidity of 58%. The data recorded includes Heath Release Rate (HRR) and Total Heat Release (THR) as shown in FIGS. 5A and 5B.

After cooling, the mattress was observed to be damaged as follows:

Mattress Cover: 60% of the cover was consumed. Internal Components: 10% consumed. Foundation: 10% consumed.

Mattress Barrier: Intact.

As a conclusion, the sample specimen met the requirements set forth in the 16 CFR 1633, Standard for the Flammability (Open Flame) of Mattresses Sets.

Example 3

A flammability test for requirements set forth in the 16 CFR 1633 on a non-limiting example of a flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes (the “test specimen”) is shown in Table 7.

TABLE 7 Test Results: Item Readings Limit Result Maximum Rate of Heat 29 200 Met Release (kW) Total Heat Release in 10 5.43 15 Met minutes (MJ)

The test specimen consisted of a single sided tight top mattress with bed base. The test specimen, after conditioning for not less than 48 hours, to 70° F. and 50% R.H., was placed underneath the collection hood. The test was started no more than 20 minutes after removal from the conditioning chamber. The specified pair of propane test burners was placed on the top panel and border as specified in the test protocol. The computer data acquisition system was started. After one minute of ambient data acquisition, the burners were ignited and left to burn for 70 seconds (top) and 50 seconds (border). After both burners were out the top burner was lifted and pinned and the apparatus was backed away from the specimen. The test was allowed to proceed until either all combustion ceased, 30 minutes passed. The test specimen was placed under the open calorimeter and tested. At the time of testing, the ambient temperature was 71° F. with a relative humidity of 45%. The data recorded includes Heath Release Rate (HRR) and Total Heat Release (THR) as shown in FIGS. 6A and 6B.

After cooling, the mattress was observed to be damaged as follows:

Mattress Cover: 40% of the cover was consumed. Internal Components: 5% consumed. Foundation: 10% consumed.

Mattress Barrier: Intact.

The test specimen met the requirements set forth in the 16 CFR 1633, Standard for the Flammability (Open Flame) of Mattresses Sets.

Example 4

A flammability test for requirements set forth in the 16 CFR 1633 on a non-limiting example of a flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes (the “test specimen”) is shown in Table 10.

TABLE 10 Test Results: Item Readings Limit Result Maximum Rate of Heat 28 200 Met Release (kW) Total Heat Release in 10 2.59 15 Met minutes (MJ)

The test specimen consisted of a single sided tight top mattress with bed base. The test specimen, after conditioning for not less than 48 hours, to 70° F. and 50% R.H., was placed underneath the collection hood. The test was started no more than 20 minutes after removal from the conditioning chamber. The specified pair of propane test burners was placed on the top panel and border as specified in the test protocol. The computer data acquisition system was started. After one minute of ambient data acquisition, the burners were ignited and left to burn for 70 seconds (top) and 50 seconds (border). After both burners were out the top burner was lifted and pinned and the apparatus was backed away from the specimen. The test was allowed to proceed until either all combustion ceased, 30 minutes passed, or the development of a fire of such size as to require suppression for the safety of the facility. The test specimen was placed under the open calorimeter and tested. At the time of testing, the ambient temperature was 68° F. with a relative humidity of 51%. The data recorded includes Heath Release Rate (HRR) and Total Heat Release (THR) as shown in FIGS. 7A and 7B.

After cooling, the mattress was observed to be damaged as follows:

Mattress Cover: 30% of the cover was consumed. Internal Components: 0% consumed. Foundation: 0% consumed.

Mattress Barrier: Intact.

The test specimen met the requirements set forth in the 16 CFR 1633, Standard for the Flammability (Open Flame) of Mattresses Sets.

Example 5

A flammability test for requirements set forth in the 16 CFR 1633 on a non-limiting example of a flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes (the “test specimen”) is shown in Table 13.

TABLE 13 Test Results: Item Readings Limit Result Maximum Rate of Heat 22 200 Met Release (kW) Total Heat Release in 10 4.42 15 Met minutes (MJ)

The test specimen consisted of a single sided tight top mattress with bed base. The test specimen, after conditioning for not less than 48 hours, to 70° F. and 50% R.H., was placed underneath the collection hood. The test was started no more than 20 minutes after removal from the conditioning chamber. The specified pair of propane test burners was placed on the top panel and border as specified in the test protocol. The computer data acquisition system was started. After one minute of ambient data acquisition, the burners were ignited and left to burn for 70 seconds (top) and 50 seconds (border). After both burners were out the top burner was lifted and pinned and the apparatus was backed away from the specimen. The test was allowed to proceed until either all combustion ceased, 30 minutes passed, or the development of a fire of such size as to require suppression for the safety of the facility. The test specimen was placed under the open calorimeter and tested. At the time of testing, the ambient temperature was 68° F. with a relative humidity of 58%. The data recorded includes Heath Release Rate (HRR) and Total Heat Release (THR) as shown in FIGS. 8A and 8B.

After cooling, the mattress was observed to be damaged as follows:

Mattress Cover: 30% of the cover was consumed. Internal Components: 0% consumed. Foundation: 0% consumed.

Mattress Barrier: Intact.

The test specimen met the requirements set forth in the 16 CFR 1633, Standard for the Flammability (Open Flame) of Mattresses Sets.

Example 6

A flammability test for requirements set forth in the 16 CFR 1633 on a non-limiting example of a flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes (the “test specimen”) is shown in Table 16.

TABLE 16 Test Results: Item Readings Limit Result Maximum Rate of Heat 25 200 Met Release (kW) Total Heat Release in 10 4.76 15 Met minutes (MJ)

The test specimen consisted of a single sided tight top mattress with bed base. The test specimen, after conditioning for not less than 48 hours, to 70° F. and 50% R.H., was placed underneath the collection hood. The test was started no more than 20 minutes after removal from the conditioning chamber. The specified pair of propane test burners was placed on the top panel and border as specified in the test protocol. The computer data acquisition system was started. After one minute of ambient data acquisition, the burners were ignited and left to burn for 70 seconds (top) and 50 seconds (border). After both burners were out the top burner was lifted and pinned and the apparatus was backed away from the specimen. The test was allowed to proceed until either all combustion ceased, 30 minutes passed, or the development of a fire of such size as to require suppression for the safety of the facility. The test specimen was placed under the open calorimeter and tested. At the time of testing, the ambient temperature was 70° F. with a relative humidity of 55%. The data recorded includes Heath Release Rate (HRR) and Total Heat Release (THR) as shown in FIGS. 9A and 9B.

After cooling, the mattress was observed to be damaged as follows:

Mattress Cover: 20% of the cover was consumed. Internal Components: 0% consumed. Foundation: 0% consumed.

Mattress Barrier: Intact.

The test specimen met the requirements set forth in the 16 CFR 1633, Standard for the Flammability (Open Flame) of Mattresses Sets.

Example 7

A flammability test for requirements set forth in the 16 CFR 1633 on a non-limiting example of a flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes (the “test specimen”) is shown in Table 19.

TABLE 19 Test Results: Item Readings Limit Result Maximum Rate of Heat 25 200 Met Release (kW) Total Heat Release in 10 3.23 15 Met minutes (MJ)

The test specimen consisted of a single sided tight top mattress with bed base. The test specimen, after conditioning for not less than 48 hours, to 70° F. and 50% R.H., was placed underneath the collection hood. The test was started no more than 20 minutes after removal from the conditioning chamber. The specified pair of propane test burners was placed on the top panel and border as specified in the test protocol. The computer data acquisition system was started. After one minute of ambient data acquisition, the burners were ignited and left to burn for 70 seconds (top) and 50 seconds (border). After both burners were out the top burner was lifted and pinned and the apparatus was backed away from the specimen. The test was allowed to proceed until either all combustion ceased, 30 minutes passed, or the development of a fire of such size as to require suppression for the safety of the facility. The test specimen was placed under the open calorimeter and tested. At the time of testing, the ambient temperature was 72° F. with a relative humidity of 56%. The data recorded includes Heath Release Rate (HRR) and Total Heat Release (THR) as shown in FIGS. 10A and 10B.

After cooling, the mattress was observed to be damaged as follows:

Mattress Cover: 20% of the cover was consumed. Internal Components: 0% consumed. Foundation: 10% consumed.

Mattress Barrier: Intact.

The test specimen met the requirements set forth in the 16 CFR 1633, Standard for the Flammability (Open Flame) of Mattresses Sets.

Example 8

A flammability test for requirements set forth in the 16 CFR 1633 on a non-limiting example of a flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes (the “test specimen”) is shown in Table 22.

TABLE 22 Test Results: Item Readings Limit Result Maximum Rate of Heat 20 200 Met Release (kW) Total Heat Release in 10 1.84 15 Met minutes (MJ)

The test specimen consisted of a single sided tight top mattress with bed base. The test specimen, after conditioning for not less than 48 hours, to 70° F. and 50% R.H., was placed underneath the collection hood. The test was started no more than 20 minutes after removal from the conditioning chamber. The specified pair of propane test burners was placed on the top panel and border as specified in the test protocol. The computer data acquisition system was started. After one minute of ambient data acquisition, the burners were ignited and left to burn for 70 seconds (top) and 50 seconds (border). After both burners were out the top burner was lifted and pinned and the apparatus was backed away from the specimen. The test was allowed to proceed until either all combustion ceased, 30 minutes passed, or the development of a fire of such size as to require suppression for the safety of the facility. The test specimen was placed under the open calorimeter and tested. At the time of testing, the ambient temperature was 68° F. with a relative humidity of 55%. The data recorded includes Heath Release Rate (HRR) and Total Heat Release (THR) as shown in FIGS. 11A and 11B.

After cooling, the mattress was observed to be damaged as follows:

Mattress Cover: 30% of the cover was consumed. Internal Components: 0% consumed. Foundation: 0% consumed.

Mattress Barrier: Intact.

The test specimen met the requirements set forth in the 16 CFR 1633, Standard for the Flammability (Open Flame) of Mattresses Sets.

A flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes as described herein, may disrupt the progress of fire by accomplishing one of the following:

(1) Physically block the advance of the flame front by establishing and maintaining a char barrier that isolates the combustible material within the barrier envelope.

(2) Restrict or otherwise limit the flow of air into the barrier envelope to help deprive the incipient fire of oxygen.

(3) Reduce the temperature at the flame front through the emission of vapor-phase flame retardants that capture free radicals at the flame front.

The “fire triangle” is used to describe the three components necessary for self-propagating combustion which are heat, fuel and oxygen. The disruption stated above may be accomplished through breaking one or more sides of the fire triangle. It is noted that an effective barrier does not have to provide all three functions to serve as a flame barrier.

A flame barrier substrate with flame-retardant properties and affinity for sublistatic dyes as described herein, may be used in a variety of ways including, but not limited to, mattress tickings, mattress border fabric, bedspreads, furniture, upholstery fabric, and so on. The flame barrier substrate seeks to address limitations inherent in prior arts in the following ways:

A flame barrier substrate that can be heat transfer printed

-   -   Heat transfer printing is the most agile printing technology. In         this technology, run size has a negligible effect on cost, but         heat transfer printing is significantly more cost-effective than         screen printing for short runs.

A flame barrier substrate that can be printed to order

-   -   The proposed invention can be produced in large lots at the         point of fabric formation and differentiated closer to the point         of sale by print pattern, color or design according to the         customer's preferences and yardage requirements     -   This reduces fashion obsolescence risk and waste while         decreasing lead time

Greater design flexibility

-   -   Near-infinite color and design possibilities     -   Optical effects (e.g., trompe l'oeil) to create the appearance         of texture     -   Rapid style changes with minimal waste

A higher perceived value versus quilted laminates and or stitchbonds

-   -   Woven fabrics are regarded as more permanent than nonwovens.     -   Heavier base weight and denser appearance conveys premium         quality

A flame barrier that has increased char strength—compared to previous solutions —after exposure to flame

-   -   Burst strength after 60 second exposure to NIST burner was 50         lbs. PSI         -   Equal to burst strength of lighter weight knits prior to             exposure.     -   Much lower propensity for cracking or breaching during or after         flame exposure

A flame barrier composed primarily of non-FR fibers—a minimum 60% of content to be non-FR fiber

A tightly constructed flame barrier made substantially from core-spun yarns whose sheath fibers melt, flow, and congeal on exposure to flame thereby filling interstices (i.e., the spaces between yarns) resulting in a char with decreased air permeability

A result of air permeability testing on the non-limiting examples of a flame barrier substrate (e.g., core-spun yarns) is as follows:

Sample# and Identification: 1-C-11/1 R11 42 ppi 2-C-11/1 R11 44 ppi 3-C-11/1 R11 46 ppi 4-C-11/1 R11 48 ppi 5-C-11/1 R11 50 ppi Item Description Units 1 2 3 4 5 Weight (osy) oz/yd² 7.28 7.36 7.52 7.68 7.84 Air Permeability (cfm) 92.0 82.0 69.0 60.3 52.7 Air Permeability After (cfm) — 56 — 56 — Burn Flammability 603 (Small Pass/Fail Pass Pass Pass Pass Pass Scale)

As shown in Samples 2 and 4 above, the air permeablities were assessed prior to and following exposure to flame.

It is also noted that some core-spun filling yarns may be eliminated if the barrier structure of a flame barrier substrate can be maintained without them. Additionally, some of the core-spun yarns may be replaced with non-core yarns as a method of reducing cost. The technical face yarns may include fibers with an affinity for sublistatic dyes. Filling yarns may include the same yarns or blends of dye receptive and functional fire-retardant (FR) fibers. Anyone familiar with weaving techniques would recognize that there are other warp-face constructions aside from twill weaves (as shown in, e.g., FIG. 2) that may be used to realize the goal of concentrating the dye-receptive yarns on the technical face of the fabric.

While the invention has been described in terms of exemplary embodiments, those skilled in the art will recognize that the invention can be practiced with modifications in the spirit and scope of the appended claims. These examples given above are merely illustrative and are not meant to be an exhaustive list of all possible designs, embodiments, applications or modifications of the invention. 

What is claimed:
 1. A flame barrier substrate, comprising: a balanced fine core-spun yarn, and a sheath of low-temperature-resistant fibers comprising non-fire retardant fibers with an affinity for sublistatic dyes, wherein the balanced fine core-spun yarn comprises a heat-stable core enveloped in the sheath of low-temperature-resistant fibers.
 2. The flame barrier substrate of claim 1, wherein the non-fire retardant fibers comprise at least one of: polyester, nylon, and any other fiber that has an affinity for sublistatic dyes.
 3. The flame barrier substrate of claim 1, wherein the non-fire retardant fibers are configured to melt in presence of a flame reducing air permeability and simultaneously depriving the potential fuel of oxygen while creating a physical impediment to progress of the flame to potential fuel within a mattress or other upholstered article thereby creating a flame barrier.
 4. The flame barrier substrate of claim 1, wherein the heat-stable core comprises at least one of: multi-filament fiberglass, aramid, and steel.
 5. The flame barrier substrate of claim 1, wherein the flame barrier substrate is configured to be used as a decorative outer fabric that comprises the side and end walls of a mattress.
 6. A method for manufacturing a flame barrier substrate with decorative or functional patterns comprising: providing a balanced fine core-spun yarn, wherein the balanced fine core-spun yarn further comprises a heat stable core enveloped in a sheath of fibers; and printing a decorative or functional patterns onto the sheath of fibers.
 7. The method of claim 6, wherein the printing comprises at least one of: digital printing, and heat-transfer printing.
 8. The method of claim 6, wherein the heat-stable core comprises at least one of: multi-filament fiberglass, aramid, and steel.
 9. The method of claim 6, wherein the sheath of fibers comprises fibers with an affinity for sublistatic dyes.
 10. The method of claim 6, wherein the sheath of fibers comprise non-fire retardant fibers that are configured to melt in presence of a flame thereby limiting air permeability for the flame and creating a physical impediment to the progress of the flame to potential fuel within a mattress or other upholstered article thereby creating a flame barrier.
 11. The method of claim 10, wherein the non-fire retardant fibers comprise at least one of: polyester, nylon, and any other fiber that has an affinity for sublistatic dyes.
 12. A method for manufacturing a flame barrier substrate with decorative or functional patterns comprising: providing a first balanced fine core-spun yarn; providing a sheath of non-fire retardant fibers with an affinity for sublistatic dyestuffs and a second balanced fine core-spun yarn; providing a sheath of fibers with fire-retardant properties; and combining the first balanced fine core-spun yarn and the second balanced core-spun yarn in a woven substrate, wherein the first core-spun yarn comprises a heat stable core, and wherein the second balanced fine core spun yarn comprises a heat stable core.
 13. The method of claim 12, wherein the fabric is configured to be engineered in a way to concentrate the sheath of non-fire retardant fibers with an affinity for sublistatic dyestuffs on one side of the substrate, thereby creating a decorative, technical face of the fabric.
 14. The method of claim 12, wherein the non-fire retardant fibers comprise at least 60% of the flame barrier substrate.
 15. The method of claim 12, wherein the heat stable core comprises at least one of: multi-filament fiberglass, aramid, and steel.
 16. The method of claim 12, wherein the sheath of fibers with fire-retardant properties comprise at least one of: modacrylics, treated cotton or rayon, fire-retardant lyocell, meta-aramids, para-aramids, fluoropolymers and copolymers thereof, chloropolymers, polybenzimidazole, polyimides, polyamideimides, partially oxidized polyacrylonitriles, novoloids, poly (p-phenylene benzobisoxazoles), poly (p-phenylene benzothiazoles), polyphenylene sulfides, flame-retardant viscose rayons, polyvinyl chloride homopolymers and copolymers thereof, polyetheretherketones, polyketones, polyetherimides, polylactides, and any combinations thereof.
 17. The method of claim 12, wherein the non-fire retardant fibers comprise at least one of: polyester, nylon, and any other fiber that has an affinity for sublistatic dyes.
 18. The method of claim 12, wherein the woven substrate comprises a twill weave or other warp face fabric.
 19. The method of claim 12, wherein the woven substrate is formed to impart a three-dimensional surface texture.
 20. A flame barrier substrate, comprising: a balanced fine core-spun yarn, and a sheath of low-temperature-resistant fibers comprising non-fire retardant fibers with an affinity for sublistatic dyes wherein the non-fire retardant fibers are configured to melt in presence of a flame reducing air permeability and simultaneously depriving the potential fuel of oxygen while creating a physical impediment to progress of the flame to potential fuel within a mattress or other upholstered article thereby creating a flame barrier, wherein the balanced fine core-spun yarn comprises a heat-stable core enveloped in the sheath of low-temperature-resistant fibers. 